Immunohistochemical Analysis of Antimelanoma Monoclonal Antibodies, with Special Reference to Fetal Tissue Distribution

An immunohistochemical study using 2 antihuman melanoma monoclonal antibodies designated as MoAb 225.28S and MoAb 653.40S was carried out on various human skin tumors, including malignant melanoma as well as on normal and fetal tissues by indirect immunofluorescence technique. Specific immunofluorescence was observed not only in malignant melanoma cells but also in cells of pigmented nevi, basal cell epithelioma, normal hair follicles, and some fetal tissues. Both monoclonal antibodies were revealed to be able to recognize the common antigenic determinant shared by several skin tumors, including malignant melanoma, and fetal tissues. Therefore, both monoclonal antibodies might recognize premature antigen of both melanocytic and keratinocytic cell lineage

Proliferating Giant Pigmented Nevus: A Report of an Unusual Tumor Occurring in Association with a Congenital Giant Pigmented Nevus

A 32-year-old Japanese woman with a giant pigmented congenital nevus of the torso presented with a massive pigmented tumor mass of the vulva which grew over an 8-year period. Histologically, the tumor was composed of benign appearing nevus-like cells with focal areas of extensive fibrous response. The tumor cells were positive for S-100 protein and with an antihuman melanoma antibody (MoAb 225, 28S) stain. Electron microscopy confirmed the nevomelanocytic nature of the tumor cells and demonstrated peculiar cytoplasmic crystalline tubular structures similar to those seen in cells infected with herpes virus type II. We propose the term “proliferating giant pigmented nevus” for this previous undescribed tumor. J Invest Dermatol 92:315S–317S, 198